JP2002014562A - Fixing pressure roller for copying machine or printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a roller having an oil barrier function which endures use over a long term. SOLUTION: In the roller of a multi-layer structure in which an inside elastic layer 2, an oil barrier layer 3 and an outside elastic layer 4 are orderly stacked toward an outer layer by having a core bar 1 as a center material, the oil barrier layer 3 is constituted of a fluororesin tube. Also, each end part of the fluororesin tube is projected and bent from a space between the inside and outside elastic layers at each end surface of the roller and an inside space formed of the inside elastic layer of the fluororesin tube and the core bar is filled or coated with a sealing material, so that it is sealed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing pressure roller used in an image forming section of an OA device such as a copying machine or a printer. More specifically, the present invention relates to a fixing pressure roller for a copying machine or a printer, which uses a release agent such as silicone oil to improve the releasability of a toner.

[0002]

2. Description of the Related Art As a fixing pressure roller used in an image forming section of a copying machine, a printer or the like, a fixing roller in which an elastic body such as silicone rubber is integrated around a cored bar is generally known. When such a roller is actually used, a releasing agent such as silicone oil is applied to the roller surface in order to improve the releasability of the toner and the fixing object (paper, etc.). However, since the elastic body itself has a property of oil storage swelling due to silicone oil, in the above roller in which the elastic body is in a single layer state, a dimensional change due to oil storage swelling of the elastic body causes a change in fixing pressure, At the same time, problems such as separation of the elastic body from the core metal are caused.

In order to eliminate such disadvantages, it has been considered to prevent the fluctuation of the fixing pressure as much as possible by enlarging the diameter of the cored bar. There is a limit naturally from such things. This has led to the use of a three-layer roller in which the elastic body is divided into an inner layer and an outer layer, and a fluororubber latex coating layer is disposed as an oil barrier layer therebetween. Here, both end surfaces of the roller are flat. That is, it means that the length of the elastic body and the length of the fluoro rubber latex along the longitudinal direction of the roller are the same.

[0004]

However, fluororubber latex is a material which functions sufficiently as an oil barrier, but has a problem that adhesion to an elastic body is weak. Further, swelling of the outer elastic layer by silicone oil or the like used as a release material promotes separation between the oil barrier layer and the outer elastic layer.
Here, the swelling of the outer elastic layer itself is not particularly a problem, but the "peeling" is a serious problem together with the peeling at the interface between the oil barrier layer and the inner elastic layer described below. Also, on each end face of the roller, a release agent such as silicone oil also penetrates into the internal elastic layer,
In addition to swelling the internal elastic layer, peeling occurs at the interface between the oil barrier layer and the internal elastic layer, resulting in a severe reduction in the service life of the roller and an increase in the frequency of roller replacement. Problems are introduced.

As described above, the conventional three-layer roller has a problem in that the releasability of the toner and the releasability of the fixing object cannot be maintained for a long period of time. Accordingly, an object of the present invention is to provide a fixing pressure roller that maintains an oil barrier function even during long-term use and has no concern about separation between an elastic material and an intermediate layer material that is an oil barrier layer. is there.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, the fluororubber latex previously used for the oil barrier layer has been replaced with an adhesive layer with an elastic layer. It has been clarified that the above problems can be solved at once when using a fluororesin material excellent in the above.

Thus, according to the present invention, there is provided a roller comprising a core metal as a center material, and an inner elastic layer, an oil barrier layer, and an outer elastic layer laminated and integrated in this order toward the outer layer. The layer is made of a fluororesin tube with improved adhesiveness to the elastic layer, and the fluororesin tube protrudes from the roller end face,
A fixing pressure roller for a copying machine or a printer, wherein a sealing material is applied or filled in an internal space formed by a fluororesin tube, an internal elastic layer, and a core metal.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. 1 and 2 show an example of a fixing pressure roller (hereinafter, simply referred to as a “roller”) of the present invention.
FIG. 1 is a transverse sectional view of the roller, and FIG. 2 is a longitudinal sectional view. In these figures, 1 is a metal core, 2 is an internal elastic layer,
3 is an oil barrier layer, 4 is an external elastic layer, and 5 is a sealing material (FIG. 2).

Here, the shape of the roller of the present invention is basically such that an inner elastic layer, an oil barrier layer, and an outer elastic layer are laminated and integrated in this order with a core metal as a central material toward an outer layer thereof. The roller is not limited to the illustrated shape as long as the oil barrier layer has a structure formed of a fluororesin tube. For example,
In order to increase the elasticity of the roller, the internal elastic layer 2 may have a two-layer structure including an elastic layer having a foamed (sponge) structure and an elastic layer having a normal solid structure.

In the roller according to the present invention, the cored bar 1 functions as a rotating shaft of the roller.
In addition to metal materials such as aluminum, steel, and various alloys, a cylindrical or cylindrical body made of ceramic or the like is used.

The material of the inner elastic layer 2 and the outer elastic layer 4 is not particularly limited as long as it has elasticity. In general, a material having excellent heat resistance such as silicone rubber or fluorine rubber is preferably used. . The thickness of the elastic layer is appropriately set according to the intended use of the roller and the core metal size,
Usually, it is preferable that the inner elastic layer 2 is in the range of 0.5 to 3.0 mm and the outer elastic layer 4 is in the range of 50 to 150 μm.

On the other hand, the oil barrier layer 3 is made of a fluororesin having particularly excellent heat resistance and oil resistance and having improved adhesion to the elastic layer. Fluororesins having excellent heat resistance and oil resistance include polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkylvinyl ether copolymer (PFA), and tetrafluoroethylene-hexafluoropropylene copolymer (FEP). Among them, among them, considering heat resistance and workability, etc.,
PFA is preferred. The thickness of the oil barrier layer 3 made of the above-mentioned fluororesin may be usually in the range of 10 to 100 μm, but in consideration of the flexibility and strength of the layer, it is particularly preferably in the range of 20 to 50 μm. . And
It is important that the oil barrier layer 3, that is, at least the inner and outer surfaces of the fluororesin tube, exhibit a state in which the adhesiveness with the elastic body is improved. For this purpose, for example, the tube may be previously subjected to a chemical treatment using a sodium metal solution method, a sodium complex solution or the like, or a treatment by laser irradiation.

Further, in the present invention, at each end face of the roller, a protrusion 3a of the oil barrier layer 3 (fluororesin tube) protruding from between the inner and outer elastic layers is bent toward the center of the roller. The sealing material 5 is filled or applied to the internal space formed by the bent tube portion, the cored bar 1 and the internal elastic layer 2. This prevents the release agent from entering the interface between the elastic layer 2 and the oil barrier layer 3 and the interface between the elastic layer 2 and the metal core 1 as well as the internal elastic layer 2. As a result, the problem of swelling of the internal elastic layer 2 due to the release agent is eliminated, and a roller having no change in fixing pressure can be obtained. In this case, the degree of protrusion of the tube may be in the range of 1 to 10 mm.
Examples of the sealing material 5 used at this time include fluorosilicone, fluororesin, and metals, but fluorosilicone is preferable in terms of chemical resistance, heat resistance, workability, and the like.

[0014]

Examples of the present invention will be described below. A core metal 1 of an aluminum alloy cylinder having an outer diameter of 38φ, a 30 μm-thick PFA tube oil barrier layer 3 whose inner and outer surfaces are chemically treated by a sodium metal solution method or a sodium complex solution method, and a cylindrical molding metal having a predetermined inner diameter. The mold was prepared.
The metal core 1 is fixed to the center of a cylindrical mold having the oil barrier layer 3 attached to the inner surface thereof using a fixing jig. Silicon rubber is injected into the space between the metal core 1 and the oil barrier layer 3 for a predetermined time. Vulcanized by heating at a temperature of 2 ° C. and an internal elastic layer 2
, A 1.0 mm thick silicone rubber was formed.

Next, silicone rubber is applied on the oil barrier layer 3 as the external elastic layer 4 in the same manner as described above.
It was formed to a thickness of μm. At this time, the PFA tube is protruded by 5 mm from between the inner elastic layer 2 and the outer elastic layer 4, and the protruding end 3a of the oil barrier layer 3 is bent toward the center of the roller, so that the core bar 1 and the inner elastic layer 2 The interior space formed between the rollers was filled with fluorosilicone as the sealing material 5 to prepare the roller of the present invention.

On the other hand, as a comparative example, a roller having the same size as the roller of the present invention was prepared in the same procedure as in the above-described example of the present invention except that the fluorocarbon rubber latex was used for the oil barrier 3. However, the fluoro rubber latex layer is
It was formed by coating after molding the internal elastic layer. For these rollers, the oil barrier layer 3 and the outer elastic layer 4
Was subjected to an adhesive strength test and a peel test by immersion in silicone oil.

The test method is described below. The adhesion strength test
A cut was made in the circumferential direction from the roller with a width of 10 mm, a sample was taken, the oil barrier layer 3 was peeled from the outer elastic layer 4, and the peel strength was measured. In the silicone oil immersion test, the roller body was immersed in silicone oil at 150 ° C., and the presence or absence of peeling between the oil barrier layer 3 and the elastic layers 2 and 4 was confirmed. The test results are shown in Table 1 below.

[0018]

[Table 1] Here, in the oil immersion for 3000 hours in the comparative example, peeling occurred between both the inner elastic layer 2 and the oil barrier layer 3 and between the outer elastic layer 4 and the oil barrier layer 3.

[0019]

From the above results, according to the present invention, it has an oil barrier function that can withstand long-term use.
A fixing pressure roller for a copying machine or a printer can be provided.

[0020]

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an example of a roller of the present invention.

FIG. 2 is a longitudinal sectional view of the roller of FIG.

[0021]

[Explanation of symbols]

 Reference Signs List 1 core metal 2 internal elastic layer 3 oil barrier layer 4 external elastic layer 5 sealing material

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F16C 13/00 F16C 13/00 EZ // B29K 27:12 B29K 27:12 B29L 31:32 B29L 31: 32 F-term (reference) 2H033 AA25 BA41 BB05 BB06 BB14 BB29 BB30 3J103 AA02 AA15 AA24 AA33 AA41 AA71 BA34 BA41 EA06 FA03 FA10 FA12 FA22 GA02 GA52 GA57 GA58 HA01 HA03 HA05 HA12 HA15 HA18 HA32 HA33 HA04 AG04 AG20 AG22 AG23 AG27 AH04 EA01 EA03 EA06 EA07 EB01 EB12 EB24 EF01 EF27 EF49 EW02 EW21 EW37

Claims (1)

[Claims] 1. A roller comprising a core metal as a center material, and an inner elastic layer, an oil barrier layer, and an outer elastic layer laminated and integrated in this order toward the outer layer, wherein the oil barrier layer is an elastic layer. Each of the ends of the fluororesin tube protrudes from between the inner and outer elastic layers on each end face of the roller, and the fluororesin tube and the inner portion thereof are formed. A fixing pressure roller for a copying machine or printer, wherein a sealing material is filled or applied to an internal space formed by an elastic layer and a cored bar.